Multidimensional rotary motion apparatus moving a reflective surface and method of operating same

ABSTRACT

A rotary motion controller controlling the motion of a mirror in a projection system is described having a mounting element coupled to a support member. A two-axis coupling is provided with at least two input shafts coupled to two drive mechanisms. A channeled portion is provided in a second of the two input shafts through which the support member extends there through and is guided thereby and where the at least one support member is coupled to the first input shafts via an input coupling coupled to and driving the support member and a control input controlling the position of the at least two input shafts. A method of controlling a mirror in an underwater projection system is also provided along with a method of operating a controller for an underwater projection system and a further embodiment for providing movement of a mirror in an underwater projector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/626,871 filed Sep. 25, 2012 and also claims the priority ofU.S. provisional patent application 61/678,622, filed Aug. 1, 2012,which are both incorporated herein by reference.

BACKGROUND OF THE INVENTION

In applications having light projection, one technique to allowmechanical motion to direct the light in the x and y axis is to use twodiscrete mirrors with one mirror allowing for rotation of the image inthe x axis which is further superimposed on another mirror allowing forfurther rotation in the y axis. An advantage of this system issimplicity—the two axes can be parked on a rotating shaft such as amotor or a galvanometer with a simple control mechanism to control theposition of the mirrors. A principal problem with this type of controlsystem is that the reflection occurs on two surfaces resulting in lossesand inaccuracies from the mirror surfaces imperfections. These issuesresult in a reduction of image intensity and quality. The two mirrorconfiguration also requires a larger size/footprint. The primary mirrormay be small but the secondary mirror, which collects all the diverginglight from the primary source will need to be larger.

In addition, various methods exist for tip and tilting, x and ytranslation, of a single reflective surface. Some of them are used insensitive applications such as in the aviation, space and medical fieldsand are very accurate, sometimes down to the milliradian. They useforces such as magnetic, mechanical, piezo, and other means oflocomotion to tilt a system that is held in either a gimbal or a balljoint. Such systems need complex and carefully manufactured electronicsto close a feedback loop allowing for proper functioning of the systemrendering and tilt systems with a single reflective surface has alimited range of motion despite the higher resolution and cost, furtherlimiting their applicability to most general applications. Alternately,other existing techniques that have a single reflective surface andemploy a mechanical system need articulated arms and carefully designedball joints to function, similarly saddling them with highermanufacturing costs and requiring larger footprints for deployment.

Another technique of enabling a single reflective surface in more thanone axis of rotation employs a primary rotation medium that is coupledto a secondary rotation medium which in turn rotates the mirror. Thesedevices actually move the second motor and as a result need more spacefor operation, again increasing the footprint of the system. Theaddition of a moving second motor adds mass to the moving components andincreases inertia. The inertia of the motor can prohibit a smaller,lower power first motor from being used or from a small first motor tomove with higher acceleration and deceleration. This higher inertia alsorenders such systems more prone to errors due to the larger movingmasses. Further because the mirror is far from the main axis ofrotation, the mirror surface has to be larger, making it impractical forlimited physical space applications. These factors contribute to makingthese systems less accurate and requiring more space in a footprint fordeployment in any control system.

Thus, there exists a need for a device and a method that provides tipand tilt control on two axis, offers the ability for systems tocalculate the relative or absolute position of the mount surface orelement quickly and efficiently, provide for fixed motors which in turnlower motor torque and provide a lower inertia of moving components andbe cost effective. The system also needs to provide the motion at highspeed, have a small form factor/net volume, use smaller motors to saveweight, reduce cost, reduce inertial interference, lower powerconsumption, and result in robust, compact, cost effective device withhigh accuracy for mechanical and electrical systems.

SUMMARY OF THE INVENTION

An aspect of the invention is to provide a compact, cost effective,higher resolution, more accurate, more repeatable rotary motion controlsuitable for use in a projection system, such as within the confines ofan underwater projection system.

A further aspect of the invention is to provide a lighter, more compactrotary motion control system.

A still further aspect is to provide a rotary motion control systemhaving less inertial interference and better acceleration/decelerationfor guiding an element mounted on a mounting member.

The invention includes a method, an apparatus, and an article ofmanufacture.

The apparatus of the invention includes a motion control system havingan at least one mounting element coupled to an at least one supportmember; a two-axis coupling having at least two input shafts coupled toan at least two drive mechanisms; an at least one channeled portion in asecond of the at least two input shafts through which the at least onesupport member extends there through and is guided thereby and where theat least one support member is coupled to the first of the at least twoinput shafts via an at least one input coupling coupled to and drivingthe at least one support member; and an at least one control inputcontrolling the position of the at least two input shafts.

The motion control system can also include an at least two indexingblades coupled to the at least two input shafts. The system furthercomprising an at least one sensor calculating a relative position of theat least two input shafts and translating said motion to a two-axisoutput, wherein an input from the at least two drive mechanisms moves atleast one of the at least two input shafts which member coupled to themounting element and the second of the at least two input shafts withinthe at least one channeled member coupled to the first of the at leasttwo input shafts such that the movement is measured by the at least onesensor and a measured two-axis output is reported to a controller.

The at least one coupling can fit within a curved portion of the atleast one channeled member having the channel therein, with the at leastone support member passing through the curved portion and the channeland coupling to the at least one coupling.

The motion control system can also include an at least one mirrorelement coupled to the support member through the at least one mountingelement. The at least one mirror element can be a flat mirror element.The at least one mounting element can also mount an at least one of amultifaceted mirror, a divergent mirror, or a spheroid mirrored shape asthe mirror element. The at least one support member can be coupledthrough the at least one mounting element to a mirror and the at leastone mounting element can be coupled to the at least one support memberthrough at least one of an angled attachment point relative to themounting member or an offset attachment point from a center of saidmounting element.

The at least one support member can be coupled to the second of the atleast two input shafts by a hinged joint with a pin member, whereby thesliding of the at least one support member within the channel and aboutthe hinge translates to movement in a pitch and a yaw axis of the atleast one support member.

The at least one of the at least one coupling, at least two inputshafts, and at least one channel are fabricated at least in part of alow friction wear surface comprising a low friction material. The lowfriction material can be a high performance polymer. The low frictionmaterial can be a High Molecular Weight Polyethylene and PolyethyleneTerephthalate. Wherein at least one of the at least one couplings, atleast two input shafts, and at least one channel are fabricated from ametal or a composite material or high performance polymer impregnatedwith a composite material.

The drive mechanisms can be magnetically or electromechanically coupledto the at least two input shafts. The motion control system can furtherinclude a chassis, the chassis supporting the at least two drivemechanisms at an angle relative to one another. The angle can besubstantially 90 degrees.

The method of the instant invention includes a method of controlling amotion control system controlling a mirror within an underwaterprojection system in a water feature, the system having an at least onedrive mechanism, with at least two input shafts coupled to and driven bythe at least one drive mechanism; a channel portion in a first of theleast two input shafts. A support member can be coupled to the second ofthe at least two input shafts, wherein the support member passes throughthe channel portion from the second of the at least two input shafts andextends to support a mirror mount where the at least one drive mechanismmoves the at least two input shafts and this movement is imparted in thesupport member and the mirror bracket mounted thereon which in turnsupports a mirror in the underwater projection system and guides animage from the underwater projection system within the water feature.

The method of the instant invention includes a method of controllingmotion in a mirror element in an underwater image projection system,comprising providing a torque input from an at least one drive mechanismon command from a controller, turning a first of an at least two inputshafts with said torque input, turning a second of an at least two inputshafts with said torque input, same with said controller, engaging an atleast one support member supporting said mirror element through thesecond of the at least two input shafts such that it slidingly engageswith a channel in a second of the at least two input shafts, and movingthe mirror through said engagement in a controlled fashion based oncommands from said controller to steer with said mirror an image in an Xaxis and a Y axis relative to said water feature from said underwaterimage projection system based on the measured relative degree of turningin each of the at least two inputs.

The method can further include providing calibration of the system froma calibration module, the calibration module receiving input correctionsprovided during or after operations and translates the input correctionsto relative X axis and Y axis movement and compensates for thesecorrections in the measured relative degree of turning in the at leasttwo input shafts when providing the X axis and Y axis outputs. Themethod of claim can also include providing feedback from a feedbackmodule, wherein the feedback module provides position feedback for afirst axis of motion and second axis of motion relative to the at leastone drive mechanism.

Moreover, the above objects and advantages of the invention areillustrative, and not exhaustive, of those which can be achieved by theinvention. Thus, these and other objects and advantages of the inventionwill be apparent from the description herein, both as embodied hereinand as modified in view of any variations which will be apparent tothose skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are explained in greater detail by way ofthe drawings, where the same reference numerals refer to the samefeatures.

FIG. 1 shows an isometric view of the rotary motion system and driver.

FIG. 2 shows a further isometric view of the rotary motion controlsystem and drive of FIG. 1.

FIG. 3 shows an isometric view of the second drive shaft of theexemplary embodiment of FIG. 2

FIG. 4 shows an isometric view of the first drive shaft coupled to thesupport shaft of FIG. 2.

FIG. 5 provides a further isometric view of the first drive shaftcoupled to the mirror support of FIG. 4 with relative motion indicated.

FIG. 6 shows a plan view for a controller for the exemplary embodimentof FIG. 1.

FIGS. 7A-7D show various shapes and configurations of mirrors and opticsthat may also be used in conjunction with the exemplary embodiments ofthe invention.

FIGS. 8A-8C show isometric left, right, and bottom views of a furtherexemplary embodiment of the rotary motion control system.

FIG. 9 shows an isometric view of the chassis of the exemplaryembodiment of FIGS. 8A-C

FIGS. 10A and 10B show the pivot member of the exemplary embodiment ofFIGS. 8A-C with the support member.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an isometric view of the rotary motion control system anddriver. The system includes a mounting element 310 coupled to and outputor support shaft 320 through a two-axis coupling generally shown as 400,500 having at least two input shafts 420, 520 which are in turn coupledto at least two drive mechanisms 110, 120, respectively. In thisexemplary embodiment shown, the at least two drive mechanisms 110, 120are shown as electromagnetic drive mechanisms 110, 120. These can bemechanically, magnetically or electromechanically coupled to the atleast two input shafts 420, 520 as best shown in FIG. 2. The twoelectromagnetic drive mechanisms 110, 120 are coupled to a chassis 200.The chassis serves to hold the motors stationary at a required positionand angle. The angle in the embodiment is 90 degrees but other anglescould also be employed without departing from the spirit of theinvention. In FIG. 1, drive mechanisms 110 and 120 represent an electricmotor. Some non-limiting examples of further mechanical driving systemsinclude but are certainly not limited to galvanometers, stepper motors,motors with gears or tranmissions, and the like. Modifications can bemade to the driving source without departing from the spirit of theinvention.

FIG. 2 shows a further isometric view of the rotator motion controlsystem and drive of FIG. 1. In this figure, the drive mechanisms 110,120 have been omitted to more clearly see the workings of theembodiment. FIG. 2 provides a clearer view of the two-axis couplingmembers 400, 500. As shown in FIG. 2, at least two indexing blades 430,530 are provided to index the at least two input shafts 420, 520, hereshown as a first input shaft 520 and a second input shaft 420, which aredriven from drive shafts 410, 510 coupled to the input shafts 420, 520and drive members. The drive members may be electrical motors, magneticdrives, piezo drives, mechanical drives, or similar devices, as notedabove.

The drive mechanisms 110, 120 move drive shafts 410 and 510 which impartmovement in the input shafts 420, 520 respectively. The, drive shafts410, 510 allow rotary torque from drive mechanisms 110, 120 to betransmitted to the coupling members 400, 500. The coupling is created inthis exemplary embodiment through keying the drive shafts 410, 510within the input shafts 420, 520. In further exemplary embodiments thedrive and input shafts may be a single component. These points ofcoupling in the exemplary embodiment of FIG. 2 are keyed to preventslippage with between the drive shaft 410, 510 and input shaft 420, 520.The coupling of the drive shafts 410, 510 may allow for a screw or otherfastening device to be used that allows for parts to be connected tothem. Each blade is coupled to the controller through optical sensors440, 540 which, in conjunction with a controller 700 index the positionof the at least two indexing blades 430, 530 and thereby the position ofthe input shafts 420, 520.

In the exemplary embodiment shown, the sensors are, as a non-limitingexample, opto-interrupter type sensors. In further exemplaryembodiments, other sensors can be used, for instance but certainly notlimited to, Hall Effect sensors, potentiometers, capacitive sensors, andthe like. The sensor type shown in the exemplary embodiment allows forthe edges of the indexing blades 430, 530 to be detected which in turnallows for detection of an absolute position for the arms. Alternately,in one of the further exemplary embodiments for instance, one can useHall Effect sensors, capacitive sensors or potentiometers to provide alinear or multi-point signal to identify the position directly. Infurther exemplary embodiments, one can couple the sensors to a differentpart of the drive mechanism, such as the other side of the motor, or toany part of the gearbox, that can allow a controller to track therelative motion and relate this to the pitch and yaw translation of thereflected image or radiation without departing from the spirit of theinvention.

The first coupling member 500 is linked to an at least one support shaft320 and the second input shaft 520 guides the support shaft 320 in an atleast one channel member 445 to facilitate controlled motion of themounting element 310. The motion of input shafts 420, 520 aretransferred through the linkage 545 or the channel member 445 which inturn propel and guide the at least one support shaft 320. The at leastone support shaft 320 passes through the channel 450 and is coupled tothe coupling member 500 by an at least one input coupling or linkage 545which is coupled to and drives the at least one support shaft 320.Although a single support shaft 320, a single channeled member 445, anda single drive or input coupling 545 are provided, additional elementsor members may be utilized without departing from the spirit of theinvention. In the exemplary embodiment shown, the at least one inputcoupling 545 fits within a curved portion of the at least one channeledmember 445, the at least one support drive or input coupling 545. The atleast one support shaft 320 supports an at least one mount element orbase 310. The exemplary embodiment shows a mirror coupled to the atleast one mount element or base 310 and the mount element or base 310being directly secured to the driven support shaft 320. However, severaldifferent techniques to attach the at least one mount element or base310 to the support shaft 320, for instance variations can be provided toaid in the manufacturability and durability of the product. Somenon-limiting examples of alternate mechanisms for coupling the drivenshaft can include designing the mirror to be inserted into a socket orcavity to ensure accurate positioning of the mirror without departingfrom the spirit of the invention. The surface that is moved by thedriven shaft may also be secured to the shaft using a screw or otherfastening mechanism or similar mechanisms. The exemplary embodimentshown uses a flat mirror, however, several different shapes of mirrorsand optics are contemplated, as further seen in FIGS. 7 A through 7D anddescribed herein below.

The at least two drive mechanisms 110, 120 input motion through an atleast two drive shafts or couplings 410, 510 which in turn move the atleast two input shafts 420, 520 respectively. The at least two inputshafts 420, 520 turn and input or indexing blades 430, 530 measures thedegree of this movement and with the controller 700 control thismovement. The at least two input shafts 420, 520 are coupled to oneanother and the at least one support shaft 320 through input coupling545 which extends from input shaft 520 and is coupled through the inputcoupling 545 to the support shaft or member 320 and the channel 450 ininput shaft 420 through which the support shaft 320 passes. In thisfashion the rotation of the drive shafts 410, 510 is translated intomotion of the respective at least two input shafts 420, 520. This motionin turn moves input shaft 520 and support shaft or member 320 about theaxis of pin 600 which guides support member or shaft 320 within thechannel 450. By sliding within channel 450 and about the hinge createdby pin 600 the pitch and yaw of support shaft 320 is achieved.

The sliding and motion of the two axis coupling can be further aided byadding lubrication to the moving parts and the channel. The lubricantmay be of any typical type, including but not limited to an oil,silicone, mineral, or similar lubricant which can be applied orcontained in a bath to adhere to the moving parts of the couplingmembers 400, 500 of the two axis coupling to allow for free and smoothlow friction motion. Additionally, the fabrication of members 300, 400,and 500 may include low friction wear surfaces which come in contactwith other moving members using low friction materials such as a highperformance polymer, such as but certainly not limited toPolyoxymethylene (POM), Polyetheretherketone (PEEK), Polyimide (PI),Polyamide (PA), Ultra High Molecular Weight Polyethylene (UHMWPE) orPolyethylene Terephthalate (PET) as non-limiting examples. Thesematerials can be used to fabricate the entirety of the component or thewear surfaces. The components in the exemplary embodiment are as anonlimiting example fabricated completely from POM. Additionalembodiments can utilize a metal, such as but certainly not limited toanodized aluminum, stainless steel, or a composite material such as areinforced graphite or high performance polymer impregnated with acomposite material, or similar compounds in the fabrication of thedevice to minimize wear and friction.

FIG. 3 shows an isometric view of the second input shaft of theexemplary embodiment of FIG. 2. As shown in the figure, an indexingblade 430 is shown with an input shaft 420 coupled thereto. A curvedsection 441 of the channeled member 445 is provided and the channel 450in the channel member 445 is shown therein. The channel 450 is createdso that the at least one support shaft or member 320 can glide throughit when propelled by the second input shaft 420. However it is thesecond indexing blade 430 that controls the position of the at least onemount element 310 in the secondary axis.

FIG. 4 shows an isometric view of the first input shaft coupled to themirror support of FIG. 2. As shown first support shaft 520 is coupled tothe mirror support 320 through input coupling 545. A central drive shaft510 is located within the first support shaft 520. As shown, this is ajoint coupling with a pin member 600, the joint coupling permittingtwo-axis motion of the mirror base 310 through the mirror support 320,as better descried in FIG. 5. The second support member 420 restrainsand guides the motion imparted by the first support member 520 allowsfor pan-yaw motion of the at least one mirror base 310. The pin 600 mayalso be but is certainly not limited to a screw, a rivet, a standoffbolt or the like. The design of the hinge member or input coupling 545may allow a screw to secure drive shaft 510 to input shaft 520,permitting only one axis of motion. Various approaches may be used toserve the function of pin 600 without departing from the spirit of theinvention.

FIG. 5 provides a further isometric view of the first input shaftcoupled to the mirror support of FIG. 4 with relative motion indicated.FIG. 5 highlights the two axis of motion available to the first inputshaft 520. A driven motion turns the input shaft 520, as shown by thearrow, in a direction based on motion imparted on the index blade 530.This can be imparted electromagnetically, as would be provided by agalvanometer or electromagnetic motor or the like, or through mechanicalmeans, such as but not limited to a stepper motor or worm gear motor orthe like. The relative motion of the blade 530 is translated veryaccurately to motion in the input shaft 520. The input shaft in turnturns as indicated. In addition, through the pinned joint of inputcoupling 545, mirror support shaft 320 is free to pivot about the pin600 in the input coupling 545. This axis of motion is restrained by thechannel 450 of the first input shaft and its channel member 445. Asnoted above, in this fashion the motion of the mirror support 310 isaccomplished and controlled.

FIG. 6 shows a plan view for a controller for the exemplary embodimentof FIG. 1. The controller 700 is coupled to or contains a Rotary MotionControl System and Driver Circuit. It provides a module for calibration750 of the system and a separate module for pan and yaw correction 760,as shown. The circuit includes sensors 440, in this case opto-isolatorsensors as discussed further herein below, 440, 540 as seen in FIG. 2 inthe system providing position feedback for the first axis of motion(Axis A) and second axis of motion (Axis B) relative to the at least twodrive mechanism alone or in conjunction with the indexing blades.Relative positions of the at least to indexing blades 430, 530 arerelated to the position of the system in the calibration module. The panand yaw correction module takes programmed corrections provided duringor after operations and translates this to relative X axis and Y axisoutputs 730, 740 respectively.

One non-limiting example of an application of the exemplary embodimentof the instant invention as shown and described herein is as the rotarymotion control system and driver circuit as a component of an underwaterprojection system secondary steering mechanism used in conjunction withan underwater DLP projection system. The second mirror functions to movereflected images from the underwater DLP projection system within adefined boundary space within a water feature such as, but not limited,to a pool as described in Applicant's co-pending U.S. patent applicationSer. No. 13/533,966, filed Jun. 26, 2012. The controller 700 may be acontroller for such an underwater projection system or a furthercontroller or a separate controller communicating with the controller700 and the modules discussed above.

FIGS. 7A-7D show various shapes of mirror elements that mayalternatively be used in conjunction with the exemplary embodiment ofFIG. 1. In addition to the flat mirror base 310 shown in FIGS. 1-6,FIGS. 7A-7D show various shapes and configurations of mirrors and opticsthat may also be used in conjunction with the exemplary embodiment.These embodiments are non-limiting examples and are provided to show thebreadth of the utility of the invention as a beam steering device. FIG.7a represents a multifaceted mirror or optic 360, having severalreflective planes and coupled to a shortened mirror support 320 andcoupling 330 that receives the pin 600 as identified above. FIG. 7Bshows a divergent mirror 350 with a generally convex shape similar to asurface portion of a sphere coupled to the mirror support 320 and thecoupling 330. FIG. 7C shows a flat mirror element 310 with an angledattachment point 770 at the attachment point of the mirror support 320and coupling 330. FIG. 7D shows an offset attachment point for a flatmirror base 310 with mirror support 320 not attaching at the center ofthe mirror base 310 but at an offset point and having the mirror support320 extend from there to the coupling 330. In addition, the supportshaft 320 and mount element 310 can attach other elements such asoptics, optical modulations, diffraction gratings, reflective surfacesand the like.

FIGS. 8A-8C show isometric left, isometric right, and isometric bottomviews of a further exemplary embodiment of the rotary motion controlsystem. The system moves a mirror member 310 on a mirror support 320. Achassis or body member 200 has an at least one motor, shown as a firstmotor 110 for imparting vertical or up-down motions in the mirrorelement 310 and a second motor 120 imparting horizontal or side to sidemotion as described herein below.

As see in FIG. 8A an at least one vertical cam 415 is coupled to thefirst or vertical drive moor 110. The cam 415 is coupled to a attachmentpoint 312 that extends from the mirror support 320. The attachment point312 is connected to the vertical cam 415 through a first of an at leasttwo drive shafts or linkages, here vertical linkage 4100. A similarsecond of an at least two drive shafts or linkages is shown in FIGS.8A-9 as horizontal linkage 5100. Additional shafts, input shafts, orlinkages may be used to couple the respective at least one cams to themirror element and impart relative motion. The vertical linkage is alsoin communication with an at least one sensor, here shown as verticalsensor 440 mounted on a sensor support 442. The sensor 440 determinesthe condition of the movement imparted to the mirror element 310 by thelinkage 4100. In this instance the at least one sensor also includes ahorizontal movement sensor 540 and a bracket or support member 542 incommunication with the horizontal linkage. The horizontal movement asdescribed herein below in relation to FIGS. 8B-10B is also therebytracked.

The motion produced by the at least one vertical cam 415 through thelinkage 4100 provides a moment of movement about a hinge 215 and hingepin 212, as better seen in relation to FIGS. 8B and 9. The movement isabout the axis of the hinge pin 212 and is shown in the figure with theaid of arrows as relative motion A. The hinge 215 acts as a firstrestraint mechanism permitting the motion indicated.

FIG. 8B shows an isometric view from the side of the device oppositethat of 8A. The hinge 215 and hinge pin 212 are more clearly seen inrelation to the mirror support 320. The at least one motor, herevertical motor 110 and horizontal motor 120, are also shown. A fixedmount 517 exists apart from the chassis 210. The mount secures a balland socket joint acting as a coupling to the second of an at least twodrive shafts or linkages, here the horizontal linkage 5100. Thehorizontal linkage 5100 is coupled by a further ball and socket couplingmechanism at an opposite end of the horizontal linkage 5100 to a furtherat least one cam, here horizontal cam 515. The horizontal cam 515 iscoupled to the drive motor 120 and acts to move the chassis 210 aboutthe ends of the horizontal linkage 5100. As noted above, a horizontalsensor 540 and support member or bracket 542 engage a sensor element 432to determine horizontal movement.

The motion of the horizontal cam 515 moves the coupling with the atleast one horizontal linkage 5100. The other end of the linkage beingfixed to the fixed mount 517, the motion is restrained and the relativedistance between the coupling points fixed. The circular motion of thehorizontal cam results in a twisting moment about the chassis 210relative to FIG. 8B shown in the figures by movement arrow B. Thistwisting moment is the horizontal movement as the device is on a pivotpoint 257, the fixed coupling acting as a second further restrainingmechanism resulting in motion about the pivot, as further shown anddescribed in relation to FIG. 8C.

FIG. 8C shows a bottom view of the exemplary embodiment of FIGS. 8A-8B.A pivot member 250 is provided passing through an element of the chassisas best seen in FIG. 9. The pivot member 250 includes a pivot membersupport body 255 and the pivot member support body 255 has or acts as oron a low friction spacer. The pivot member 250 further includes a pivotpin 257 that allows for movement as indicated by movement arrow B, aboutthe axis of the pivot pin 257. This is imparted by the translation ofthe horizontal cam 515 imparting motion through the couplings to thehorizontal linkage 5100. As noted previously a sensor 540 and bracket542 are provided to sense the horizontal position of the device.

FIG. 9 shows a further isometric view of the chassis of the exemplaryembodiment of FIGS. 8A-8B. As more clearly seen in this view the hinge215 and pivot pin member hole 251 are clearly seen. It is about the axisof these two elements the chassis is moved to import both pitch and yawor vertical and horizontal motion in the mirror element 310. In the caseof the up-down or vertical motion provided by the vertical linkage 4100,the hinge 215 and hinge pin or member 212 restrain the devices relativemotion. Further, the inset nature of the pivot member prevents unbridledmovement and limits the motion imparted to rotation about an axis,namely the axis of the pivot pin. As best shown by the arrows showingrelative motion.

FIGS. 10A and 10B show the pivot member 250 of the exemplary embodimentof FIGS. 8A-C with the pivot member support body 255. The pivot member250 includes the pivot pin 257. The pivot pin 257 is oriented such thatthe chassis 210 rests atop of it. It is held by the pivot member supportbody 255. The pivot member support body 255 passes through the pivotmember hole 251. The pivot pin 257 is in contact with the pivot membersupport body 255. The pivot member support body 255 is provided with aslot 810 which corresponds to a groove 825 on the pivot pin 257. Thepivot pin 257 is slidingly coupled to the pivot member support body 255.This is one example of providing the pivot pin 257, further variationsin the exact members may be provided such that a pivot pin 257 supportsthe chassis 210 and allows for the movement indicated.

Thus through the at least one cam, here horizontal and vertical cams,coupled to the mirror support member 320 through an at least twolinkages and restrained by a hinge member and a pivot member, the mirrorelement 310 is provided both vertical or up down movement as well ashorizontal or side to side movement in the further embodiment.

The embodiments and examples discussed herein are non-limiting examples.The invention is described in detail with respect to preferredembodiments, and it will now be apparent from the foregoing to thoseskilled in the art that changes and modifications may be made withoutdeparting from the invention in its broader aspects, and the invention,therefore, as defined in the claims is intended to cover all suchchanges and modifications as fall within the true spirit of theinvention.

What is claimed is:
 1. A motion control system controlling a mirror element within an underwater projection system in a water feature, pool, or spa, the system comprising: a first drive mechanism and a second drive mechanism; a first cam mechanism driven by the first drive mechanism and a second cam mechanism driven by the second drive mechanism; a first input shaft coupled to and driven by the first cam mechanism and a second input shaft coupled to and driven by the second cam mechanism; and a mirror support member having a mirror element thereon coupled to the first input shaft, the mirror support member restrained by a first restraint mechanism so as to move about a moment in a first direction by the first input shaft, the mirror support member also restrained by a second restraint mechanism through the first restraint mechanism, so as to move the mirror support member about a moment in a second direction by the second input shaft acting on the second restraint mechanism through the second cam mechanism and the second drive mechanism, and this movement is imparted in the mirror support member and the mirror element mounted thereon which in turn guides an image from the underwater projection system within the water feature, pool or spa.
 2. The system of claim 1, wherein the first restraint mechanism is a hinge and the first input shaft rotates the mirror support member about a hinge pin.
 3. The system of claim 2, wherein the second restraint mechanism is a pivot and the second input shaft rotates the mirror support member about a pivot point.
 4. The system of claim 3, wherein the first restraint mechanism or the second restraint mechanism results in vertical movement of the mirror element relative to the water feature, pool or spa.
 5. The system of claim 4, wherein the first restraint mechanism or the second restraining restraint mechanism results in horizontal movement of the mirror element relative to the water feature, pool or spa.
 6. The system of claim 3, wherein the first restraint mechanism or the second restraint mechanism results in vertical movement of the image by the mirror element relative to the water feature, fountain, pool or spa.
 7. The system of claim 3, wherein the first restraint mechanism or the second restraint mechanism results in horizontal movement of the mirror element relative to the water feature, fountain, pool or spa.
 8. The system of claim 1, further comprising a control input controlling a position of the first and second input shafts and a first sensor and a second sensor tracking a position of the mirror element via relative positions of the first and second input shafts.
 9. The system of claim 1, further comprising a low friction spacer and a chassis, wherein the chassis supports the first and second drive mechanisms and the spacer supports the chassis at the second restraining mechanism and eases the movement of the mirror support member about a moment in either the first or second directions.
 10. The system of claim 9, wherein the first and second sensors further comprise optical interruption sensors.
 11. A motion control system controlling a mirror element within an underwater projection system in a water feature, pool, or spa, the system comprising: a base; a first drive mechanism coupled to the base; a second drive mechanism coupled to the base; a first linkage coupled to and driven by the first drive mechanism; a second linkage coupled to and driven by the second drive mechanism; and a mirror support member having a mirror element thereon coupled to the first linkage and the base, wherein the mirror support member is coupled to the base by a first restraint mechanism, which limits the motion imparted on the mirror support member by the first linkage to a first plane, and wherein the second linkage acts upon the second drive mechanism to rotate the base and the mirror support member about a second restraint mechanism in a second plane.
 12. The system of claim 11, wherein the first restraint mechanism is a hinge and the mirror support member rotates about a hinge pin.
 13. The system of claim 12, wherein the second restraint mechanism is a pivot pin and the base and the mirror support member rotates about an axis of the pivot pin.
 14. The system of claim 13, further comprising a low friction spacer positioned between the base and the pivot pin configured to allow the base to rotate in relation to the pivot pin upon actuation of the second drive mechanism.
 15. The system of claim 11, further comprising an at least one control input controlling a position of the first linkage and the second linkage and tracking a position of the mirror element via relative positions of the first linkage with a first sensor and the base with a second sensor.
 16. The system of claim 15, wherein the first sensor and the second sensor are optical interruption sensors.
 17. The system of claim 11, wherein the first restraint mechanism or the second restraint mechanism results in vertical movement of an image by the mirror element relative to the water feature, fountain, pool or spa.
 18. The system of claim 11, wherein the first restraint mechanism or the second restraint mechanism results in horizontal movement of the mirror element relative to the water feature, fountain, pool or spa.
 19. The system of claim 11, wherein the first plane and the second plane are orthogonal to each other. 